How Do Kegs Work

I been searching and searching and can't seem to find an answer. My best guess is that the outlet, where the beer comes out, is attached to a tube or pipe that runs down to almost the bottom of the keg. Then the inlet, where the co2 comes in, just goes straight in the top, where there is no fluid. Therefore, when the co2 pushes against the top of the liquid, its forced out through tube/pipe. My question is: if this is how a keg works, won't there always be a little bit of beer left at the bottom? If this is the case, how would I get to that last little bit? Obviously with a hombrew keg you could just open her up and enjoy, but I'm dealing with commercial brew right now.

Yes, you will always have a tiny bit left. The bottom is cone shaped to direct all the liquid to the center where the dip tub picks it up. the closer the dip tube is to the bottom the more you pick up. You will not get it all. You'll likely have less than a pint left though. not enough to worry about.

Excellent, that is good to know. Thank you for your reply.

Some people even shorten the pick-up tube so they pick up less sediment from the bottom of the keg. I leave mine full length. Once the keg goes into the fridge I don't touch it. With a new keg there may be one glass worth clouded with yeast & sediment but after that the beer runs clear as long as I don't disturb the keg.